46 
THE GEOOOGIST. 
which means a constant irrigation is formed from below, upwards^ 
each plant forming a system of syphons. By these means 
the water is continually in movement, and being frequently in 
contact with the atmosphere, emits azote and thus prevents the 
putrefaction of the mass of which the turf bed is forming. 
M. Fee remarked that the lichen Cladonia raugiferina decays 
from time to time in its undergrowth, and continues to vegetate 
on the surface of the mould thus formed. 
9. Do certain plants belong exclusively to specific Geological 
formations ? answered by M. Kirschleger. 
From the comparison of the flora of the Granitic Vosges and 
Jura our author forms three categories : — 1. the plants peculiar 
to the Jura. 2. Those common both to the Vosges and Jura. 
3. Those peculiar to the Yosges. 
The number of alpine plants of the Jura (whose habitats are 
between 830 to 1600 metres of altitude) is 350 ; of the Vosges 
250; 60 are peculiar to the granitic Vosges, 140 to the chalk 
of the Jura, 210 are found both on the Jura and the Vosges ; 
total number of alpine plants 410, of which number the habitats 
of 195 are situate between 1200 and 1600 metres of altitude. 
Hence it appears that the flora of the Jura is more varied than 
the granitic Vosges and there are plants which prefer the chalk 
to the granite; it does not stand to reason however, that we 
must hence conclude that the Jurassic plants are not found else- 
where on primitive rocks. 
M. Schultz has been engaged during several years on the ex- 
amination of the geographical distribution of plants in difi'erent 
countries ; he had long believed that there are those peculiar to 
certain formations, but of late years he has determined that this 
cannot be admitted as a general law. It is true that in some 
countries the rule holds good, but in others the same plants are 
found in totally difi'erent formations. In the envirions of Bitche 
for example, on a space of 43 square kilometres, on which two 
formations exist, the Vosges sandstone and the muschelkalk. 
